Recent studies on hypnosis have suggested that delusions can be temporarily created in healthy subjects (see work by Amanda Barnier and Rochelle Cox). When you are given a hypnotic suggestion that you will see a stranger when you look in the mirror, it is probable that your behaviour in the hypnotic session will strikingly resemble that of a patient with a delusion of mirrored self misidentification. Both the hypnotic subject and the delusional patient deny that they see themselves in the mirror and claim instead that they see a stranger who looks a bit like them. Their beliefs are resistant to challenges and often accompanied by complex rationalisations of their weird experience.
Why would we want to create delusions in healthy subjects? It’s difficult to study the phenomenon of delusions in the wild, and especially the mechanisms responsible for their formation. Here are some reasons why we may need the controlled environment of the lab:
1. it is not always possible to investigate a clinical delusion in isolation from states of anxiety or depression that affects behaviour - comorbidity makes it harder to detect which behaviours are due to the delusion under investigation, and which are present for independent reasons;Evidence from the manifestation of hypnotically induced delusions has the potential to inform therapy for clinical delusions. Moreover, the use of hypnosis as a model for delusions can also inform theories of delusion formation, as analogies can be found in the underlying mechanisms. There are good reasons to expect that the hypnotic process results in neural patterns that are similar to those found in the clinical cases.
2. ethical considerations significantly constrain the type of questioning that is appropriate with clinical patients because it is important to avoid causing distress to them, and to preserve trust and cooperation, which are beneficial for treatment;
3. for delusions that are rare, such as the delusion of mirrored self misidentification, it is difficult to find a sufficient number of clinical cases for a scientific study.
Given that during the hypnotic session healthy subjects engage in behaviour that is almost indistinguishable from that of clinical patients, reflecting on this promising research programme can not only help the science of delusions, but also invite us to challenge the perceived gap between the normal and the abnormal.
[This is Lisa's last guest post. Thanks, Lisa!]